6c5t
PPARg LBD bound to SR11023
Structural highlights
DiseasePPARG_HUMAN Note=Defects in PPARG can lead to type 2 insulin-resistant diabetes and hyptertension. PPARG mutations may be associated with colon cancer. Defects in PPARG may be associated with susceptibility to obesity (OBESITY) [MIM:601665. It is a condition characterized by an increase of body weight beyond the limitation of skeletal and physical requirements, as the result of excessive accumulation of body fat.[1] Defects in PPARG are the cause of familial partial lipodystrophy type 3 (FPLD3) [MIM:604367. Familial partial lipodystrophies (FPLD) are a heterogeneous group of genetic disorders characterized by marked loss of subcutaneous (sc) fat from the extremities. Affected individuals show an increased preponderance of insulin resistance, diabetes mellitus and dyslipidemia.[2] [3] Genetic variations in PPARG can be associated with susceptibility to glioma type 1 (GLM1) [MIM:137800. Gliomas are central nervous system neoplasms derived from glial cells and comprise astrocytomas, glioblastoma multiforme, oligodendrogliomas, and ependymomas. Note=Polymorphic PPARG alleles have been found to be significantly over-represented among a cohort of American patients with sporadic glioblastoma multiforme suggesting a possible contribution to disease susceptibility. FunctionPPARG_HUMAN Receptor that binds peroxisome proliferators such as hypolipidemic drugs and fatty acids. Once activated by a ligand, the receptor binds to a promoter element in the gene for acyl-CoA oxidase and activates its transcription. It therefore controls the peroxisomal beta-oxidation pathway of fatty acids. Key regulator of adipocyte differentiation and glucose homeostasis. Acts as a critical regulator of gut homeostasis by suppressing NF-kappa-B-mediated proinflammatory responses.[4] [5] [6] Publication Abstract from PubMedPeroxisome proliferator activated receptor gamma (PPARgamma) is a nuclear receptor and target for antidiabetics that increase insulin sensitivity. Owing to the side effects of PPARgamma full agonists, research has recently focused on non-activating ligands of PPARgamma, which increase insulin sensitivity with decreased side effects. Here, we present the crystal structures of inverse agonist SR10171 and a chemically related antagonist SR11023 bound to the PPARgamma ligand-binding domain, revealing an allosteric switch in the activation helix, helix 12 (H12), forming an antagonist conformation in the receptor. H12 interacts with the antagonists to become fixed in an alternative location. Native mass spectrometry indicates that this prevents contacts with coactivator peptides and allows binding of corepressor peptides. Antagonists of related nuclear receptors act to sterically prevent the active configuration of H12, whereas these antagonists of PPARgamma alternatively trap H12 in an inactive configuration, which we have termed the tumble and trap mechanism. PPARgamma in Complex with an Antagonist and Inverse Agonist: a Tumble and Trap Mechanism of the Activation Helix.,Frkic RL, Marshall AC, Blayo AL, Pukala TL, Kamenecka TM, Griffin PR, Bruning JB iScience. 2018 Feb 27;5:69-79. doi: 10.1016/j.isci.2018.06.012. Epub 2018 Jul 2. PMID:30123887[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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